Patent GB-891152-A (GB)
Title: A method and apparatus for continuously changing the structure of substances or mixtures of such substances
IPC: B01F11/02
Filed: 1958-06-03
Abstract: A method of continuously changing the structure of gaseous, liquid and/or solid substances or mixtures of such substances by subjecting the substances to vibrations at frequencies up to high supersonic frequencies for dissolving, atomizing, decomposing, homogenizing and carrying out chemical reactions and processes comprises distributing portions of the substances into a plurality of chambers disposed on a generally circular line, subjecting the substances while within the chambers to oscillations in a direction generally tangential to the circular line, transferring portions of the substances from the chambers into a plurality of further chambers radially spaced from the first chambers on a generally circular line substantially concentric with the first line, and subjecting the substances while within the further chambers to oscillations in a direction generally tangential to the second line.  Apparatus, Figs. 1 and 3, for carrying out the method comprises annular rows of oscillatory members 4, 5, 6 mounted on a rotor disc 7 and co-operating with annular rows of oscillatory members 17 to 20 mounted on a stator 16, each pair of adjacent oscillatory members 4 to 6 enclosing acoustic chambers 8, 9, 10 and each pair of adjacent oscillatory members 17 to 20 enclosing acoustic chambers 21 to 24.  The acoustic chambers become smaller and greater in number, and the oscillatory members thinner, in the radial outward direction.  The axial distance between the rotor and stator, which may be varied, may be constant, as shown, or increase radially outwardly.  The rotor 2 has an inner annular row of members 3 for centrifugal acceleration of the substances to be treated.  The members 3 may, however, be replaced by means, e.g. a pressure pump, located inside the sound generator, or by a head of liquid upstream, or a suction pump downstream, of the generator.  A conical member 30 fixed on the driving shaft 1 enters into a hollow space 31.  An inlet pipe 25 and a delivery pipe 26 connected to a collecting channel 13 are provided with valves 28, 29 respectively.  The peripheral surfaces of the members 3 and of the oscillatory members 4 to 6 and 17 to 20 may be arranged on surfaces of variable diameter.  The oscillatory members may <PICT:0891152/III/1> <PICT:0891152/III/2> <PICT:0891152/III/3> be made of a metal or a metal alloy or of an elastically bendable material, e.g. spring steel or plastic.  The inner surface of the generator contacting the substances to be treated may be covered with an abrasion proof, or corrosion proof, protecting layer.  By reason of the construction and operation of the generator, the substances will, during their passage through the apparatus, be fed along a spiral consisting of stages 56, Fig. 3.  By suitable choice of the total number of oscillatory members and with sufficiently high speeds, e.g. 50 revolutions per second, acoustic frequencies of more than 20 kilocycles per second, e.g. between 1,000 and 10,000, may be obtained.  The oscillatory members may be perforated or they may be in the form of needles. The axis of rotation of the generator may be horizontal, as shown, vertical or inclined.  In a modification, Fig. 4 (not shown), the apparatus has only two rows of oscillatory members and acoustic chambers respectively on its rotor and stator.  In another modification, Fig. 5, the driving shaft 1 is extended into the inlet tube 25, the extension of the shaft carrying a pump rotor 37 and a propeller 40. A stationary distributer 38 and guide baffles 39 may be provided. The oscillatory members 18 of the stator are webs clamped at both ends.  In another modification, Fig. 6 (not shown), the oscillatory members are mounted on oppositely-rotatable rotors.  The apparatus may be arranged in a multi-stage unit, Fig. 7 (not shown).  In one example, a 20% concentration of kaolin in water and having the particle sizes of the kaolin ranging between 1 mm. and 20 mm. is treated.  It is stated that during a transit time of one second of the mixture through the apparatus, the kaolin is homogeneously decomposed and suspended in the water at a particle size of the order of microns.  In another example, an alkali metal silicate in liquid state and an acid, or an electrolytically-active salt, are fed separately in controlled quantities into the apparatus to form a gel.